Usually, we all experience thoughts of loving kindness, generosity, inner peace and freedom from conflicts. But these thoughts are fleeting and will soon be replaced by other thoughts, including afflictive ones such as anger and jealousy. To fully integrate altruism and compassion in our midstream, we need to do more than that. We need to cultivate them over longer periods of time. We need to bring them to our minds and then nurture them, repeat them, preserve them, enhance them, so that they gradually fill our mental landscape in a more durable way.
To arouse loving kindness, one might imagine, for instance, a young child, and feel nothing but benevolence toward that child. When that mental state has clearly arisen in one's mind, one let it grow and sustain it until if fills one's whole mental landscape. Then one will simply nurture this state, keeping it present, full and vast. If one does so regularly, the mind will become more easily and naturally filled with benevolence and loving kindness for all, and compassion for those who suffer.